Shifting device for shifting transmission

ABSTRACT

The shifting arrangement for a manual transmission, in which at least one transmission gear can be engaged or released by the simultaneous control of two shifting elements (synchronizing clutches), comprises two rotor elements which have guideways and are guided on a shifting shaft. One of the two rotor elements is non-rotatably but axially displaceably connected with the shifting shaft and is displaceable relative to the other rotor element.

The invention is based on a shifting arrangement for a manualtransmission according to the type of the main claim.

From German Patent Document DE-42 05 671 A1, a manual transmission isknown in the case of which individual transmission gears are shifted bythe interaction of several pairs of gear wheels (range shifting). Forthe shifting operation, the controlling of two synchronizing operationsis required. In order to be able to carry out the actual shiftingoperation in as brief a time as possible, the two synchronizingoperations should take place as simultaneously as possible.

From European Patent Document EP 0 547 007 A1, a shifting arrangement isknown in the case of which the shifting elements (synchronizingclutches) of a manual transmission are moved by way of shift forkswhich, in turn, are displaced by a rotationally moved shift roller. Forthis purpose, a guiding arm of the shift fork is moved in a guideway ofthe shift roller. By the interaction of the guiding arm and theguideway, the rotational movement of the shift roller is changed into anaxial displacement of the shift fork. Although, in the case of ashifting arrangement of this type, several shift forks of the manualtransmission are guided in guideways of the shift rollers extendingside-by-side and are moved by them, a simultaneous moving of two shiftforks and therefore of two synchronizing clutches is not easilypossible. Since, because of component and manufacturing tolerances, thecontrol paths of the synchronizing clutches and shift forks are notcompletely identical, it may happen that one synchronizing clutch isalready completely engaged while the other has not yet covered the wholecontrol path. Because of the narrow guiding of the guiding arms in theguideways which is required for a precise control, a tolerancecompensation is not possible.

The invention is therefore based on the object of developing a shiftingoperating for a manual transmission in which two shifting elements(synchronizing clutches) must be moved simultaneously for the shiftingof at least one transmission gear. In this case, the shifting operationis to be carried out in a secure manner and the path differences duringthe controlling of the individual shifting elements occurring because ofcomponent and manufacturing tolerances are to be compensated.

According to the invention, this object is achieved by means of thecharacterizing features of the main claim. By placing the shifting pathson at least two separate rotor elements, between which the compensationelement is arranged, a sufficient separation of the two individualshifting operations is possible because the rigid coupling of theshifting elements to be moved is eliminated. Because of the compensationelement between the two separate rotor elements, a path compensation ispossible which compensates the different operating paths of the twoshifting elements.

The shifting arrangement can be manufactured in a particularly simplemanner and with low component expenditures if the at least two separaterotor elements are guided on a common shaft and are moved by it.

The compensation of the different control paths of the two shiftingelements to be controlled simultaneously is permitted in a particularlysimple manner if one of the two rotor elements is non-rotatably butaxially displaceably arranged on the shifting shaft and the compensationelement arranged between the rotor elements is a spring element. This,on the one hand, permits a continued rotation of the axially fixed rotorelement or of the shifting shaft if the individual shifting operationcontrolled by means of the axially displaceable rotor element hasalready been carried out. On the other hand, because of the axialdisplaceability of the one rotor element, the individual shiftingoperation carried out therewith can be completed if the secondindividual shifting operation has already been carried out. Theremaining path of the shifting element (synchronizing clutch), which isrequired for the control operation, can be followed by the axiallymovable shifting element.

A tolerance compensation in both directions can be carried out in aparticularly advantageous manner if the axially displaceable rotorelement is acted upon by mutually oppositely operating spring elements,in which case it is held in a prestressed neutral position by means ofthe two spring elements and is displaceable against the effect of onespring element in each of the two axial directions.

In a particularly advantageous development of the invention, anadjustment of the neutral position of the axially displaceable rotorelement is possible in a simple manner if at least the spring elementsare constructed as a compression spring whose axial dimension isdetermined by boundary devices. By means of this fixing of the axialdimension, a precise end position is assigned which corresponds to thecentral or neutral position of the axially movable rotor element. Ahigh-expenditure adjustment of the interacting spring elements or acompensation of the different spring prestresses or characteristicspring curves is not required.

Additional advantages and advantageous further developments of theinvention are found in the subclaims and in the specification.

An embodiment of the invention will be explained in detail in thefollowing description and drawing.

FIG. 1 is a schematic representation of a manual transmission;

FIG. 2 is a partial sectional representation of the shiftingarrangement.

The manual transmission 1 illustrated in FIG. 1 has an input shaft 2constructed as a hollow shaft, an output shaft 3 which extends axiallyin parallel to the input shaft 2 and is partially guided in the hollowshaft, and an intermediate shaft 4 which is guided axially in parallelto both shafts. Five gear wheels 5 to 9 are non-rotatably mounted on theintermediate shaft 4. Four loose wheels 10 to 13 are guided on theoutput shaft 3, the loose wheel 10 meshing with the gear wheel 6, theloose wheel 11 meshing with the gear wheel 7 and the loose wheel 12meshing with the gear wheel 8. By way of an intermediate wheel 14, whichis used, among other things, for controlling the reverse gear, the loosewheel 13 meshes with the fixed gear wheel 9. Another loose wheel 15 isdisposed on the input shaft 2 and meshes with the fixed gear wheel 5.Two synchronizing clutches 16 and 17 are non-rotatably disposed on theoutput shaft 3, the synchronizing clutch 16 interacting with the loosewheel 10 (individual shifting operation C) and the loose wheel 11(individual shifting operation D). The synchronizing clutch 17 interactswith the loose wheel 12 (individual shifting operation E) and the loosewheel 13 (individual shifting operation F). A third synchronizing clutch18 is non-rotatably disposed on the input shaft 2 and, on the one hand,interacts with the loose wheel 15 (individual shifting operation A) and,on the other hand, with the loose wheel 10 (individual shiftingoperation B).

The synchronizing clutches 16 to 18 are each disposed non-rotatably butaxially displaceably on the input shaft 2 and the output shaft 3. By theaxial displacing of the synchronizing clutches, by way of thecorresponding individual shifting operations, the respectively assignedloose wheels are non-rotatably connected with the shaft. For example,for engaging the first gear, the controlling of the synchronizing clutch18 and of the synchronizing clutch 17 is required. In this case, thesynchronizing clutch 18 is engaged with the loose wheel 15 (individualshifting operation A), and the synchronizing clutch 17, by way of theindividual shifting operation E, is engaged with the loose wheel 12. Theflux of force through the manual transmission 1 is clearly and directlyshown in the illustration according to FIG. 1. The whole gear shiftpattern will not be shown in detail because it is not essential to theinvention. However, it is easily derived from the transmissionarrangement illustrated in FIG. 1 and is explained in detail, forexample, in the initially mentioned German Patent Document DE 42 05 671A1. However, it is easily possible, by means of the shifting arrangementdescribed in detail in the following, to also control other manualtransmissions in the case of which at least one transmission gear isengaged by the simultaneous controlling of two individual shiftingoperations (synchronizing operations).

As mentioned above, the synchronizing clutches 16 to 18 arenon-rotatably but axially displaceably disposed on the assigned shafts2, 3. The controlling of the individual shifting operations takes placein a manner known per se by the axial displacing of shift forks 19 whichinteract with the synchronizing clutches and of which, for reasons ofclarity, only one is shown in FIG. 2. This shift fork 19 is fastened ona shift rod 20 which is axially displaceable by way of a shift finger 21which is guided in a guide groove 22 of an intermediate member 23. Theintermediate member 23 has a sleeve-shaped construction and is disposedon a guide rod 24 and can be axially moved on it. By way of a guide bolt25, the intermediate member 23 is connected with the shiftingarrangement 26.

The shifting arrangement 26 consists essentially of a shifting shaft 27and of two rotor elements 28 and 29. On the end side, the shifting shaft27 is disposed by means of two bearings 30, 31 in the transmission caseof the manual transmission which is not shown in detail. The shiftingshaft is rotated in steps by means of a step-by-step system which isknown per se and of which only the driving part 32 is shown here whichis non-rotatably connected with the shifting shaft 27. Instead of beingrotated by a mechanical step-by-step system, the shifting shaft can alsobe rotated by an electric motor. The first rotor element 28 is fastenedon the shifting shaft 27. On its outer circumference, this rotor element28 has two surrounding guideways 33, 34 which interact either directlywith a shift finger 21 or indirectly by way of an intermediate member 23with one shift fork 19 respectively. By way of the guideway 33, thesynchronizing clutch 18 is controlled, while the guideway 34 interactswith the synchronizing clutch 16. The second rotor element 29 isnon-rotatably but axially displaceably disposed on the shifting shaft27. On its outer circumference, a surrounding guideway 35 is constructedin which the guide bolt 25 of the intermediate member 23 is guided.Between the first rotor element 28 and the second rotor element 29, acaptive spring element 36 is arranged whose axial dimension is boundedby a ring element 37 with surrounding shoulders 38. By means of one ofthe two shoulders 38, the spring element 36 rests against the firstrotor element 28. On the opposite side, the spring element 36 rests bymeans of a retaining ring 39, on the one hand, on the shoulder 38 and,on the other hand, on a surrounding projection 40 of the second rotorelement. By means of the axial course of the surrounding projection 40on the second rotor element 29, its axial displacement path is limitedin the direction of the first rotor element 28 in that the rotor element29 comes to rest against the ring element 37 by means of its interiorface 41.

On the opposite face, an analogously constructed compensating element 42is mounted which also consists of a spring element 36, a ring element 37with shoulders 38 and of a retaining ring 39. By means of a shoulder 38of the ring element 37, the spring element 36 rests on the one sideagainst a retaining ring 43 inserted in the shifting shaft 27. On theopposite side, the spring element 36 rests, by means of the retainingring 39, on the one side, against a surrounding shoulder 44 of thesecond rotor element 29. On the other side, the spring element 36 restsby means of this retaining ring 39 against the shoulder 38 of theretaining ring. The shoulder 38 of the ring element 37 facing the secondrotor element 29 can dip into a surrounding recess 45 of the rotorelement 29. The axial course of this recess 45, analogously to thesurrounding projection 40, limits the displacement path of the rotorelement 29 after the rotor element has come to rest against the rightring element 37.

By the clamping-in of the axially movable rotor element 29, aspring-centered center position is predetermined. Because of theconstruction of the spring elements as captive springs, the centerposition of the axially movable rotor element 29 is easily adjustablewithout having to take into account possibly different characteristicspring curves or spring prestresses. By means of the axial mobility ofthe rotor element 29, a compensation is possible of the differentcontrol paths while the individual shifting operations take placesimultaneously. If, in the example of the above-described first gear,the individual shifting operation A interacting with the guideway 33 isconcluded first, the individual shifting operation E can be securelycompleted because of the pulling effect of the synchronizing clutchwhich is known per se. If, in contrast, the individual shiftingoperation E is concluded first, a continued rotation of the shiftingshaft 27 is possible in which case, because of the interaction of theguideway 35 and the guide bolt 25, the rotor element 29 is axiallydisplaced while simultaneously the remaining shifting path of theindividual shifting operation A is continued by the further rotating ofthe rotor element 28.

In contrast to the embodiment illustrated here, it is possible to coupleone, several or all shift forks directly with one of the rotor elements.Instead of being carried out by means of the shift forks, the shiftingoperation can also be carried out, for example, by way of swingingforks, in which case these are also coupled directly or indirectly withthe guideway of one of the rotor elements.

In order to permit a compensation of the different shifting controlpaths in each shifting operation, the guideways must be assigned to theindividual rotor elements such that, in the case of each shiftingoperation, with the simultaneous control of two shifting elements, bothrotor elements or one of the guideways situated on them is effective.If, as illustrated in the embodiment, several guideways are arranged onone of the rotor elements, it should be ensured that no shiftingoperation is required during which the two shifting elements assigned tothe individual shifting operations must be moved through guidewaysarranged on a rotor element.

I claim:
 1. Shifting arrangement for controlling the shifting elementsof a manual transmission which, for shifting the transmission gears, areaxially displaceable parallel to an associated transmission shaft, atleast one transmission gear being engaged or disengaged by thesimultaneous controlling of two of the shifting elements, comprising atleast two rotatable separate shifting rotor elements with at least twoshifting paths which operatively interact with transmission devices forconverting rotating movement into translational movement of the shiftingelements, wherein the shifting paths are constructed on the separaterotor elements, with at least one of said shifting rotor elements beingaxially displaceable with respect to the other of said rotor elements,and a compensation element is arranged between shifting the rotorelements.
 2. Shifting arrangement according to claim 1, wherein the tworotor elements are arranged on a common shifting shaft, and one rotorelement is fixedly connected with this shafting shaft.
 3. Shiftingarrangement according to claim 1, wherein the two rotor elements arenon-rotatably connected with one another, and the compensation elementis a spring element.
 4. Shifting arrangement according to claim 3,wherein the axially displaceable rotor element is acted upon in theaxial direction by mutually oppositely acting spring elements. 5.Shifting arrangement according to claim 3, wherein the spring element isa compression spring whose axial dimension is bounded by boundaryelements.
 6. Shifting arrangement according to claim 3, wherein stopsbound the axial displacement of the displaceable rotor element. 7.Shifting arrangement according to claim 1, wherein the two rotorelements have a sleeve-shaped construction and at least partially coverone another in an axial dimension thereof.